22.1.1 Overview of The Lisp Printer

Common Lisp provides a representation of most objects in the form
of printed text called the printed representation.
Functions such as print take an object
and send the characters of its printed representation to a stream.
The collection of routines that does this is known as the (Common Lisp) printer.

Reading a printed representation
typically
produces an object that is equal to the
originally printed object.